2 results about "Diisopropanolamine" patented technology

This invention relates to a method for preparing a composite tanning agent, the composite tanning agent itself, and the tanning method thereof. The method involves preparing 5-50 parts by weight of glutaraldehyde, 5-20 parts by weight of diisopropanolamine, 5-50 parts by weight of zirconium sulfate, and 2-50 parts by weight of phosphate ester. A measured amount of water is added to a reaction vessel, and stirring is started. Diisopropanolamine is added and stirred until completely dissolved, with the temperature controlled at ≤40℃. Glutaraldehyde is slowly added, and after the addition is complete, the mixture is stirred for 30-60 minutes to obtain an aldehyde-amine modified intermediate. Zirconium sulfate is added to the intermediate, and the reaction is stirred for 40-60 minutes, controlling the pH of the entire system to 3.5-4.0. Phosphate ester is added, and the reaction is stirred for 20-30 minutes, adjusting the pH of the entire system to 3.8-4.2. The mixture is then filtered to obtain the composite tanning agent. The obtained composite tanning agent has the following advantages when tanning leather: low free aldehydes, high stability, high tanning efficiency, excellent leather-forming properties, and is environmentally friendly and chromium-free.

The application discloses an engineered decarboxylase polypeptide and a method for preparing isopropanolamine, which can synthesize isopropanolamine from L-threonine or a fermentation broth containing L-threonine by using the engineered decarboxylase polypeptide. Compared with a naturally occurring wild-type decarboxylase, the engineered decarboxylase polypeptide has improved properties, such as increased enzyme activity, increased thermal stability, good substrate tolerance and the like. The reaction conditions tolerated by the engineered decarboxylase polypeptide are more relaxed, and the reaction is more conducive to scale-up. The method for preparing isopropanolamine provided by the application can avoid the process of flammable and explosive toxic epoxide compounds or ammonia under high temperature and high pressure, greatly saves energy and equipment investment, and does not contain the classic diisopropanolamine, triisopropanolamine and polyether impurities in chemical synthesis, and has important industrial application value.